On Apr 10, 2022, at 12:56, LonDek <londekpolska@...> wrote:

?

Jerry, I have measured 32mV.

Jules, It does work, but 90% of signal is white noise alone. There are no 50Hz components visible to me in EQ, so that tells me everything should be grounded properly.

Also in sound test you can hear me tapping and blowing air into mic.

I've tried 2 different capsules, no difference. These 2 capsules work well with simple P48 circuit.

niedz., 10 kwi 2022 o 15:13?Jerry Lee Marcel <jerryleemarcel@...> napisa?(a):

If you connect a 1G resistor in series with the multimeter, it forms a voltage divider by 1/1000, so every mV you me??? asure is an acual volt at the circuit's output. You should measure 80mV.

Le 10/04/2022 à 13:50, LonDek a écrit?:

I've connected 1 gigaohm resistor in series with multimeter, and then measured milivolts. Everything is still invalid, voltages are same as without 1gohm resistor.

niedz., 10 kwi 2022 o 06:25?Jerry Lee Marcel <jerryleemarcel@...> napisa?(a):

Actually, once the capacitor is charged, there is no more current drawn, except the fraction of femtoAmpere due to residual resistance of the insulating materials, which is way higher than gigaohms.
In normal circumstances, no current should go through the 1G resistors, except during the transient charging phase.

Le 09/04/2022 à 22:05, Jules Ryckebusch a écrit?:

That would actually cause what you are seeing. Big?question: Does it work when providing bias voltage to the capsule? Remember?those are literally?a 50-100pF capacitor?that we are charging up to provide?a static bias too. They draw minimal current and most is to the 1Gig resistor to ground that develops the signal.?

Jules

On Sat, Apr 9, 2022 at 2:12 PM LonDek <londekpolska@...> wrote:

Hello

The internal resistance of my meter appears to be 955kOhm so about 1MOhm.

Best regards

Wiktor Molak

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Best Regards,

Jules Ryckebusch

214 399 0931